Duvain, his birth name Saithor, was raised as a servant within House Aearanel. While in his teens, he crossed paths with Lady Faerwen, the daughter of Lord Aearon, and the two became smitten with each other. For some time, they met and stole moments in secret, due to the scrutiny that would come from an affair with such differences in their standings. During the time, Dinenor came to try to recruit Duvain into the Illumin more than once, though Duvain refused him, wanting to remain close to Faerwen. The affair was eventually discovered, however, and Duvain was cast out from the House. Official records show that he was hanged for his transgression.

Duvain agreed to become Dinenor's apprentice only after that happened, and he changed his name to avoid suspicion. He strongly suspected Dinenor was the one to betray his secret, though he never found any proof of it. Despite of his lingering suspicions, Duvain took to Illumination well, and came to greatly prefer doing that and living within the city to being a servant. Though romantically involved with Dinenor during the majority of his apprenticeship, Duvain only began to feel attachment to the man after several months.

He met Sage after Lord Carmanadh's return to Dol Amroth, and developed a fast friendship with him. He also seemed to build an infatuation with Oendir.

As Dol Amroth descended into chaos due to Lady Gwenithel's and Lord Aearon's plot to assassinate the Prince, Dinenor was poisoned and attacked in Duvain's stead. Near death, he told Duvain of a letter that would explain everything. Duvain found the letter after Dinenor was rushed away to be treated, which revealed him as Lord Aearon's illegitimate son, and the last heir of House Aearanel. It also made Lady Faerwen his half-sister: A piece of knowledge he still struggles with.

After the execution of Gwenithel and Aearon, efforts were made to find Aearon's last son. Wishing for things to remain as they were, Duvain chose to act in anonymity, and asked for House Aearanel to be dissolved for good, its wealth scattered to various charities and causes.

With the city calm again, Duvain continues his apprenticeship, and remains living contentedly with a recovered Dinenor.